Metabolic improvements following Roux-en-Y surgery assessed by solid meal test in subjects with short duration type 2 diabetes

Sudha S Shankar,Robert V Considine,David E Kelley,Chan R Beals,Deborah L Miller,Samer G Mattar,Robin Chisholm,Anthony J Acton,Manu Chakravarthy,S Aubrey Stoch,Lea Petry,Rosemarie Jones,Lori A Mixson

doi:10.1186/s40608-017-0149-1

Abstract

BackgroundGlucose homeostasis improves within days following Roux-en-Y gastric bypass (RYGB) surgery. The dynamic metabolic response to caloric intake following RYGB has been assessed using liquid mixed meal tolerance tests (MMTT). Few studies have evaluated the glycemic and hormonal response to a solid mixed meal in subjects with diabetes prior to, and within the first month following RYGB.MethodsSeventeen women with type 2 diabetes of less than 5 years duration participated. Fasting measures of glucose homeostasis, lipids and gut hormones were obtained pre- and post-surgery. MMTT utilizing a solid 4 oz chocolate pudding performed pre-, 2 and 4 weeks post-surgery. Metabolic response to 4 and 2 oz MMTT assessed in five diabetic subjects not undergoing surgery.ResultsSignificant reductions in fasting glucose and insulin at 3 days, and in fasting betatrophin, triglycerides and total cholesterol at 2 weeks post-surgery. Hepatic insulin clearance was greater at 3 days post-surgery. Subjects exhibited less hunger and greater feelings of fullness and satisfaction during the MMTT while consuming 52.9 ± 6.5% and 51.0 ± 6.5% of the meal at 2 and 4 weeks post-surgery respectively. At 2 weeks post-surgery, glucose and insulin response to MMTT were improved, with greater GLP-1 and PYY secretion. Improved response to solid MMTT not replicated by consumption of smaller pudding volume in diabetic non-surgical subjects.ConclusionsWith a test meal of size and composition representative of the routine diet of post-RYGB subjects, improved glycemic and gut hormone responses occur which cannot be replicated by reducing the size of the MMTT in diabetic subjects not undergoing surgery.Trial registrationClinical Trials.gov Identifier: NCT00957957 August 11, 2009.

Highlights

Glucose homeostasis improves within days following Roux-en-Y gastric bypass (RYGB) surgery
Of great interest is the observation that the Roux-en-Y gastric bypass (RYGB) procedure improves both fasting and dynamic measures of glucose homeostasis well before significant weight loss, resulting in the concept that RYGB surgery “cures diabetes” through mechanism(s) that are separable from weight loss itself [1,2,3,4]
While it is likely that no one mechanism is solely responsible for the acute improvements in glucose homeostasis, studies designed to test each mechanism independently often require post-surgery patients to engage in ingestive behavior that is not congruent with the intent of the surgery, such as consuming large caloric loads that match pre-surgery intake and which do not reflect the behavioral responses that occur postsurgery

Summary

Introduction

Glucose homeostasis improves within days following Roux-en-Y gastric bypass (RYGB) surgery. The dynamic metabolic response to caloric intake following RYGB has been assessed using liquid mixed meal tolerance tests (MMTT). Few studies have evaluated the glycemic and hormonal response to a solid mixed meal in subjects with diabetes prior to, and within the first month following RYGB. It has been shown that the cognitive and sensory effects of food form alter ingestive behavior with oral-liquid and perceived gastric-liquid preloads eliciting greater postprandial hunger and lower fullness sensations, more rapid gastric-emptying and orocecal transit times, attenuated insulin and glucagon-like peptide 1 release, and lower ghrelin suppression than did responses after oral-solid and perceived gastric-solid treatments [22]

Objectives

Methods

Results

Discussion

Conclusion